adjust errors and logger (#10)

internal/errors/os_errors.go

@@ -0,0 +1,23 @@
+package errors
+
+import "net/http"
+
+func OpenFileFailed(path string, cause error) *Error {
+	return Newf(cause, http.StatusInternalServerError, "failed to open file: %s", path).WithStack()
+}
+
+func StatFileFailed(path string, cause error) *Error {
+	return Newf(cause, http.StatusInternalServerError, "failed to stat file: %s", path).WithStack()
+}
+
+func ReadFileFailed(path string, cause error) *Error {
+	return Newf(cause, http.StatusInternalServerError, "failed to read file: %s", path).WithStack()
+}
+
+func IncompleteRead(cause error) *Error {
+	return New(cause, http.StatusInternalServerError, "incomplete header read during decryption").WithStack()
+}
+
+func WriteOutputFailed(cause error) *Error {
+	return New(cause, http.StatusInternalServerError, "failed to write output").WithStack()
+}